1. Field of the Invention:
The present invention relates to a long-acting diclofenac sodium preparation, and, more particularly, to a long-acting diclofenac sodium preparation comprising a sustained-release diclofenac sodium component which is prepared by coating a sustained-release coat onto a pharmaceutical composition comprising diclofenac sodium and an organic acid.
2. Description of the Background
The utility of diclofenac sodium, which is a kind of non-steroidal anti-inflammatory drug, is highly appreciated because of its strong anti-inflammatory and analgesic actions. Diclofenac sodium is thus widely used clinically. The blood concentration half life of this compound is, however, very short. This necessitates nuisance of administering the compound three times a day, each time after meal. This nuisance leads to patient non-compliance such as failure of taking the compound. This is the situation unfavorable to the proper clinical control. Another problem involving diclofenac sodium administration is a significant side effect due to a rapid increase in the blood concentration. Demand has therefore existed for the development of a long-acting diclofenac sodium preparation which is capable of exhibiting the effect of diclofenac sodium in a most safe and efficacious manner over a long period of time.
In view of this situation, the present inventors carried out research related to a sustained-release diclofenac sodium component. As a result, the inventors have found that a sustained-release diclofenac sodium component which is prepared by coating a sustained-release coat onto a pharmaceutical composition comprising diclofenac sodium and an organic acid is able to suppress the diclofenac concentration in blood and to maintain the concentration constant over a prolonged period of time.